(1) Field of the Invention
The present invention relates to packaging and particularly to the fabrication of packages from pre-formed blanks of packaging material by a process which includes the application of an adhesive followed by folding. More specifically, the present invention is directed to apparatus for conveying pre-formed blanks of packaging material to a packaging station and especially to feeding paper blanks to a folding station via an adhesive applying station. Accordingly, the general objects of the present invention are to provide novel and improved methods and apparatus of such character.
(2) Description of the Prior Art
While not limited thereto in its utility, the present invention is particularly for employment in the packaging of cigarettes, and particularly in combination with so-called "bottom-folding" or "side-folding" packaging machines. In such machines it is known to feed the outer paper blanks, from which the packages will be formed, to a folding station by means of a conveying system comprising cooperating rollers. These rollers are driven at a constant speed and convey the blanks against a stop. An adhesive is applied to the blanks during their movement and, if appropriate, the blanks are also grooved and cut. When the moving blanks contact the stop there is a possibility that they will rebound therefrom, particularly in high-speed packaging equipment, and as a result of such rebounding the blanks may be incorrectly aligned at the time they are engaged by the actual package forming apparatus. While it is possible to provide alignment means for the conveyed package blanks, in order to overcome the problem of inaccurate orientation at the folding station take-over position, to do so requires that the packaging system be increased in complexity and expense and, because of the increased complexity, there is a decrease in reliability.
It is to be noted that, in cellophaning machines, it is known to transport regenerated cellulose film blanks continuously by means of a pair of spacially separated suction belts. In such machines, for example as disclosed in published European patent application No. 0,071,736, the otherwise finished cigarette package or other product being wrapped is periodically pushed between the suction belts. The package engages the regenerated cellulose film and is subsequently urged, together with the film, into a folding turret or a folding. shaft. An adhesive coated paper blank, however, cannot be treated in the same manner as a regenerated cellulose film since this would require that the adhesive coating be applied to the side of the packaging material which faces the suction belts, i.e., the cigarette block could not be pushed through the glue or other adhesive coating so as to be properly supported on the blank. Further, a system which employs a pair of spacially displaced suction belts cannot be adapted for turret-type packaging machines since in such machines the blanks are pushed from turret to turret in an axial direction whereas only a radial pushing movement is possible in cellophaning machines. Also, such pushing action, with the continuously moving blank still being held by suction, would not result in sufficiently accurate orientation of an outer-paper blank from which a soft package is to be formed.